Low profile catheter valve

ABSTRACT

Disclosed herein is a low profile catheter valve comprising a movable sealer portion positioned within the inflation lumen of a catheter. The sealer portion forms a fluid tight seal with the inflation lumen by firmly contacting the entire circumference of a section of the inflation lumen. The sealer portion may be positioned proximally of a side-access inflation port on the catheter, to establish an unrestricted fluid pathway between the inflation port and an inflatable balloon on the distal end of the catheter. As desired, the clinician may move the sealer portion to a position distal of the inflation port, thereby preventing any fluid from being introduced into or withdrawn from the balloon via the inflation port.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional of application Ser. No.08/812,139, filed Mar. 6, 1997, now abandoned, which is acontinuation-in-part of application Ser. No. 08/650,464 filed on May 20,1996 now abandoned, the entirety of which is incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention generally relates to catheters, and in particular,to a low profile catheter valve which may be opened to permit inflationor deflation of a catheter balloon, such as an occlusion balloon, andwhich may be closed when it is desirable to maintain the catheterballoon in an inflated state.

Guidewires are conventionally used to guide the insertion of variousmedical instruments, such as catheters, to a desired treatment locationwithin a patient's vasculature. In a typical procedure, the clinicianforms an access point for the guidewire by creating an opening in aperipheral blood vessel, such as the femoral artery. The highly flexibleguidewire is then introduced through the opening into the peripheralblood vessel, and is then advanced by the clinician through thepatient's blood vessels until the guidewire extends across the vesselsegment to be treated. Various treatment catheters, such as a balloondilatation catheter for a percutaneous transluminal coronaryangioplasty, may then be inserted over the guidewire and similarlyadvanced through vasculature until they reach the treatment site.

In certain treatment procedures, it is desirable to successivelyintroduce and then remove a number of different treatment catheters overa guidewire that has been placed in a particular location. In otherwords, one treatment catheter is “exchanged” for another over a singleguidewire. Such an exchange typically involves withdrawing the treatmentcatheter over the guidewire until the treatment catheter is fullyremoved from the patient and the portion of the guidewire which extendsfrom the patient. The guidewire is then available to act as a guide fora different treatment catheter.

In emboli containment devices, which typically utilize two occlusionballoons to form a chamber, it may be desirable to exchange therapeuticcatheters without deflating the occlusion balloons. Further, it issometimes advantageous to anchor the guidewire during the exchange. Ascan be readily appreciated, the withdrawal of treatment catheters over aplaced guidewire may result in the guidewire being displaced from itsposition. To overcome this difficulty, the prior art has developed“anchorable” guidewires, which generally feature some structure on theirdistal ends to releasably secure the guidewire at a particular locationin the patient for the duration of the medical procedure. One suchanchorable guidewire is disclosed in U.S. Pat. No. 5,167,239 to Cohen etal., which discloses a hollow guidewire with an inflation lumen and anexpandable balloon on its end. The Cohen guidewire is positioned in thesame manner as a conventional wire guidewire, but once placed, itsexpandable balloon is inflated to contact the surrounding vasculature,thereby preventing the guidewire from being displaced.

Because a permanent inflation manifold, of the type used withconventional catheters having an inflatable balloon, would prevent othercatheters from being inserted over the Cohen guidewire, the Cohen devicealso includes a removable inflation manifold, and a check valve tomaintain the balloon in the inflated state when the manifold is removed.The check valve apparatus used by the Cohen device is relatively bulky,and is described as having an outer diameter in its preferred embodimentof 0.0355 inches. Consequently, any treatment catheter intended to beinserted over the Cohen device must have an interior guidewire lumenlarger than the outer diameter of the Cohen valve, which for thepreferred embodiment, requires an interior lumen with a diameter of morethan 0.0355 inches.

As is readily appreciated by those of skill in the art, increasing theinterior lumen size of a treatment catheter results in an increase inthe outer diameter of the treatment catheter. For treatment procedureswhich take place in vasculature having a large blood vessel diameter,such as iliac arteries, a treatment catheter guidewire lumen of a sizenecessary to accommodate devices such as those described by Cohen wouldhave little or no affect on the ability of the catheter to fit withinthe blood vessel. However, many blood vessels where it is desirable toapply catheter treatment are quite narrow. For example, the leftcoronary arteries are blood vessels having diameters ranging from 2 to 4mm, and are susceptible to plaque. It would be desirable to use acatheter exchange treatment procedure, such as angioplasty, to treatsuch lesions, but the narrow diameter of the coronary vessels makes useof anchorable guidewires having large valve diameters impractical.

Consequently, there exists a need for a very low profile catheter valvewhich can be used with a hollow guidewire.

SUMMARY OF THE INVENTION

The present invention provides a catheter valve which is capable of verylow profiles, and is especially advantageous for use with anchorableguidewires, as well as therapeutic or occlusion devices. Byincorporating the valve of the present invention into such devices, itis possible to manufacture anchorable guidewires and occlusion devicecatheters with outer diameters of 0.014 inches or smaller.Advantageously, by utilizing the present invention in these catheters,clinicians will be able to use anchorable guidewires, therapeutic orocclusion device catheters in much narrower blood vessels than in thepast.

In one aspect of the present invention, there is provided a valve whichcomprises a flexible elongate tubular body having a proximal end and adistal end. The tubular body has a central lumen extending between theproximal and distal ends. The central lumen has an opening at theproximal end.

An expandable member, such as an inflatable balloon, is positioned onthe distal end of the tubular body. The expandable member is in fluidcommunication with the central lumen. An access opening is provided onthe tubular body. The access opening is in fluid communication with thecentral lumen to permit the expandable member to be actuated bypressurizing the access opening.

A sealing member is provided having a sealer portion which seals againsta surface of the tubular body. The sealing portion of the sealing memberis movable relative to said surface of the tubular body between twopositions. In the first position, the sealer portion is positioned incontact with the tubular body surface at a location which blocks theflow of fluid to or from the expandable member through the accessopening to maintain actuation of the expandable member. In the secondposition, the sealer portion is positioned at a location which permitsthe flow of fluid to or from the expandable member through the accessopening to permit actuation or deactuation of the expandable member.

In one preferred embodiment, the sealing member has a portion whichextends from the proximal end of the tubular body, and the applicationof a longitudinal force on the extending portion results in movement ofthe sealer portion in the direction of the applied force. In otherembodiments, rotational forces may be used to move the sealing member.

The sealer portion is preferably formed of a polymeric material, such asPEBAX, silicone, C-FLEX(TM) or gels. The sealer portion should becapable of withstanding balloon inflation pressures and preventsubstantially all fluid from passing to or from the expandable memberthrough the access opening when the sealer portion is positioned distalto the access opening. Advantageously, the outer diameter of the tubularbody is generally larger than the outer diameter of any portion of thesealing member or sealer portion. In some embodiments, the outerdiameter of the tubular body is no greater than 0.038 inches, preferablyno greater than 0.020 inches, and more preferably no greater than 0.014inches. Other embodiments may have larger outer diameters for thetubular body. The tubular body may also have positive stops to preventwithdrawal of the sealing member from the opening.

In another aspect of the present invention, there is provided anapparatus, comprising a hollow metallic guidewire having a central lumenand a side-access port in fluid communication with the lumen. Aninflatable balloon is mounted on the guidewire, the inflatable balloonbeing in fluid communication with the central lumen, such that fluidintroduced through the side-access port can be used to inflate theballoon.

A valve is mounted to slide along a surface of the guidewire, the valvemovable between first and second positions, one of the positions sealingthe central lumen such that substantially no fluid may pass to or fromthe inflatable balloon by way of the side-access port.

Preferably, the hollow guidewire has an outer circumference defining afirst value, and wherein the movable valve has a circumference which isless than the first value. It is also preferred that the hollowguidewire have an outer circumference of 0.12 inches or less, morepreferably 0.08 inches or less, and optimally 0.044 inches or less, andthat the movable valve have a diameter not substantially larger thanthat of the hollow guidewire.

In another aspect of the present invention there is provided a lowprofile catheter valve which comprises a sealing member capable of beingmovably inserted through a proximal opening on a catheter into aninflation lumen of the catheter. The catheter has a side-accessinflation port and an inflatable balloon in fluid communication with theside-access inflation port. A sealer portion is on the sealing member,the sealer portion being capable of forming a fluid tight seal with theentire circumference of a section of the lumen, such that substantiallyall fluid may not pass the sealer portion at normal balloon inflationpressures.

When the sealer portion is positioned within the lumen proximally of theside-access inflation port, an unrestricted fluid pathway is establishedbetween the side-access inflation port and the balloon. When the sealerportion is positioned within the lumen distally of the side-accessinflation port, substantially all fluid may not pass to or from theballoon through the side-access inflation port at normal ballooninflation pressures.

In another aspect of the present invention, there is provided a methodof inflating a catheter balloon. The first step of the method involvesproviding a tube having a proximal end and a distal end. The proximalend of the tube has an inflation opening to an inflation lumen and thedistal end has an inflatable balloon in fluid communication with theinflation lumen. A pressurized inflation fluid is then introducedthrough the inflation opening to inflate the balloon. The inflationopening may then be sealed by moving a sealing member within theinflation lumen without reducing the pressure of the pressurized fluid,wherein the step of sealing is performed without substantial deflationof the inflated balloon. Finally, the pressure of the pressurized fluidmay be reduced after completing the sealing step.

In another aspect of the present invention, there is provided a lowprofile catheter valve for use with an inflation adaptor. The valvecomprises a sealing member capable of being movably inserted through aproximal opening on a catheter into an inflation lumen of the catheter.The catheter has an inflation opening and an inflatable balloon in fluidcommunication with the inflation opening. Indicia are present on thecatheter and/or sealing member, the position of the indicia being suchthat the inflation opening is aligned with a fluid tight inflationchamber of the inflation adaptor when the catheter and sealing memberare secured in the inflation adaptor.

A sealer portion is mounted on the sealing member. The sealer portion iscapable of forming a fluid tight seal with the entire circumference of asection of the lumen, such that substantially all fluid may not pass thesealer portion at normal balloon inflation pressures. When the sealerportion is positioned proximally of the inflation opening, anunrestricted fluid pathway is established between the inflation openingand the balloon. When the sealer portion is positioned distally of theinflation opening, substantially all fluid may not pass to or from theballoon through the side-access inflation port.

In another aspect of the present invention, there is provided aninflation adaptor for introducing inflation fluid into an inflation portof an elongate tube. The inflation adaptor comprises a housing havingfirst and second portions which interact to releasably retain a sectionof the tube therein. The housing has a chamber which receives theinflation port. An inflation inlet configured to be connected to asource of inflation fluid that supplies said fluid under pressure ispositioned on the housing.

A seal which releasably seals the portions of said housing togetherprovides a fluid pathway between the inflation inlet and the inflationport, so that fluid may be supplied to the inflation port underpressure. An actuator, mounted on said housing, drives a member withinthe tube to control fluid flow through said inflation port.

In another aspect of the present invention, there is provided aninflation adaptor for introducing inflation fluid into an inflation portof an elongate tube. The inflation adaptor comprises a housing havingfirst and second portions. The two portions form a mouth for receiving asection of the tube which includes the inflation port. The mouth formsan opening having a height at least as great as the outer diameter ofthe tube such that the section of tube is insertable into the mouth fromits side in a direction transverse to the longitudinal axis of the tube.The housing also has an inflation chamber and an inflation inlet forintroducing inflation fluid under pressure into the inflation chamber.The inflation chamber releasably seals the inflation port to theinflation inlet to form a fluid passage there between.

In another aspect of the present invention, there is provided aninflation adaptor for introducing inflation fluid into an inflation portof an elongate tube. The tube has an inflatable member mounted thereonand an inflation lumen between the inflation port and the inflatablemember. The adaptor has a housing configured to seal over the tubularbody to create a fluid tight seal. An inflation inlet is on the housing,for establishing a fluid pathway between the inflation inlet and theinflation port to permit the inflatable member to be inflated. Thehousing is detachable from the tube without deflating the inflatedinflatable member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a catheter incorporating the low profile valveof the present invention.

FIG. 2 is an enlarged view of the proximal portion of the catheter ofFIG. 1, showing an exterior view of the catheter segment featuring thelow profile valve of the present invention.

FIG. 3A is a longitudinal cross-sectional view of the catheter segmentof FIG. 2, showing the low profile valve in the open position.

FIG. 3B is a longitudinal cross-sectional view of the catheter segmentof FIG. 2, showing the low profile valve in the closed position.

FIG. 4 is a longitudinal cross-sectional view of an alternativeembodiment, showing the low profile valve in the closed position.

FIG. 5 is a longitudinal cross-sectional view of the embodiment of FIG.4, showing the low profile valve in the open position.

FIG. 6 is a longitudinal cross-sectional view of an alternativeembodiment of the low profile valve, depicting the valve in the openposition

FIG. 7 is a longitudinal cross-sectional view of the embodiment of FIG.6, depicting the valve in the closed position.

FIG. 8 is a perspective view of an inflation adapter used to manipulatethe low profile valve of the present invention.

FIG. 9A is a perspective view of the interior of the inflation adapterof FIG. 8.

FIG. 9B is a perspective view of a catheter with a sealing member andalignment indicia being positioned in the inflation adaptor of FIG. 9A.

FIG. 10 is an end view of an alternative embodiment of the inflationadaptor.

FIG. 11 is a cross-sectional view of the inflation adaptor of FIG. 10along lines 10—10.

FIGS. 12 and 13 are exploded views of alternative embodiments of the lowprofile valve of the present invention.

FIG. 14 is an alternative embodiment of the valve of the presentinvention featuring a built in spring bias.

FIGS. 15A and 15B are longitudinal cross-sectional views of the catheterproximal end of FIG. 14, showing the valve in the closed and openposition, respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, there is depicted a catheter 10 incorporating thelow profile valve of the present invention. Although illustrated in thecontext of a simple occlusion balloon catheter, having a singleinflation lumen and a single inflatable balloon, it is to be understoodthat the low profile valve of the present invention can be readilyadapted to a wide variety of balloon catheters, including those havingadditional functionalities, structures, or intended uses. For example,the low profile valve could be easily adapted to catheters havingexpandable members other than occlusion balloons, such as therapeuticdilatation balloons. Furthermore, the low profile valve of the presentinvention may also be incorporated into catheters having two or morelumens. The manner of adapting the low profile valve of the presentinvention to catheters having these various functionalities, structures,or intended uses will become readily apparent to those of skill in theart in view of the description which follows.

Catheter 10 generally comprises an elongate flexible tubular body 18extending between a proximal control end 12 and a distal functional end14. Tubular body 18 has a central lumen 40 which extends between ends 12and 14. Lumen 40 has an opening 23 at proximal end 12, and is sealedfluid tight at distal end 14. The length of tubular body 18 may bevaried considerably depending upon the desired application. For example,where catheter 10 is to be used as a guidewire for other catheters in aconventional percutaneous transluminal coronary angioplasty procedureinvolving femoral artery access, lengths of tubular body 18 in the rangeof from about 120 to about 300 centimeters are preferred, with a lengthof about 180 centimeters often being used. Alternately, for a differenttreatment procedure, not requiring as long a length of tubular body 18,shorter lengths of tubular body 18 may be provided.

Typically, tubular body 18 will have a generally circularcross-sectional configuration with an outer diameter within the range offrom about 0.010 inches to 0.044 inches. Optimally, in most applicationswhere catheter 10 is to be used as a guidewire for other catheters, theouter diameter of tubular body 18 ranges from 0.010 inches to 0.038inches, and preferably is 0.020 inches in diameter or smaller, morepreferably 0.014 inches in outer diameter or smaller. The diameter oflumen 40 will be dictated, in part, by the outside diameter of tubularbody 18. For example, where tubular body 18 has an outer diameter of0.014 inches, central lumen 40 may have an inner diameter of from about0.008 inches to about 0.010 inches. The diameter of lumen 40 should belarge enough to incorporate the low profile valve described below, andlarge enough to permit sufficient fluid passage for balloon inflation.

Noncircular cross-sectional configurations of lumen 40 can also beadapted for use with the low profile valve of the present invention. Forexample, triangular rectangular, oval, and other noncircularcross-sectional configurations are also easily incorporated for use withpresent invention, as will be appreciated by those of skill in the art.The manner of adapting the valve of the present invention will becomereadily apparent in view of the description which follows.

In the preferred embodiment, the tubular body 18 functions as aguidewire, and thus, tubular body 18 must have sufficient structuralintegrity, or “pushability,” to permit catheter 10 to be advancedthrough vasculature to distal arterial locations without buckling orundesirable bending of tubular body 18. It is also desirable for tubularbody 18 to have the ability to transmit torque, such as in thoseembodiments where it may be desirable to rotate tubular body 18 afterinsertion into a patient. A variety of biocompatible materials, known bythose of skill in the art to possess these properties and to be suitablefor catheter manufacture, may be used to fashion tubular body 18. Forexample, tubular body 18 may be made of stainless steel, or may be madeof polymeric materials such as nylon, polyamide, polyimide,polyethylenes, or combinations thereof. In one preferred embodiment, thedesired properties of structural integrity and torque transmission areachieved by forming tubular body 18 out of an alloy of titanium andnickel, commonly referred to as nitinol. In a more preferred embodiment,the nitinol alloy used to form tubular body 18 is comprised of about50.8% nickel and the balance titanium, which is sold under the tradename Tinel (TM) by Memry Corp. It has been found that a catheter tubularbody having this composition of nickel and titanium exhibits greatflexibility and improved kink resistance in comparison to othermaterials. One preferred embodiment of tubular body 18 is disclosed inour copending application entitled HOLLOW MEDICAL WIRES AND METHODS OFCONSTRUCTING SAME, Ser. No. 08/812,876 filed on the same date as thepresent application, now U.S. Pat. No. 6,068,623 the entirety of whichis incorporated herein by reference.

The distal end 14 of catheter 10 is provided with an atraumatic distaltip 16, and an inflatable balloon 20, as illustrated in FIG. 1.Inflatable balloon 20 may be made from any of a variety of materialsknown by those of skill in the art to be suitable for balloonmanufacture. For example, inflatable balloon 20 may be formed ofmaterials having a compliant expansion profile, such as polyethylene orlatex. In one preferred embodiment, where inflatable balloon 20 is to beused as an occlusion balloon, it is preferably formed of a blockcopolymer of styrene-ethylene-butylene-styrene (SEBS), sold under thetrade name C-FLEX (TM). One preferred embodiment of a C-FLEX occlusionballoon is disclosed in our copending application entitled PRE-STRETCHEDCATHETER BALLOON, Ser. No. 08/812,139 now abandoned, filed on the samedate as the present application, the entirety of which is incorporatedherein by reference. Alternately, in those embodiments where inflatableballoon 20 is to serve as a dilatation balloon, it may be formed ofmaterials having a noncompliant expansion profile, such as polyethyleneterephthalate. Inflatable balloon 20 may be attached to tubular body 18in any manner known to those of skill in the art, such as heat bondingor through use of adhesives.

As shown in FIG. 1, catheter 10 is provided with a side-access inflationport or opening 22 formed in tubular body 18 at a point severalcentimeters distal from opening 23. Inflation port 22 is in fluidcommunication with central lumen 40 extending through tubular body 18. Afill hole (not shown) is formed in tubular body 18 within the regionenclosed by inflatable balloon 20, such that fluid passing throughinflation port 22 and into lumen 40 may inflate balloon 20. Conversely,an inflated balloon 20 can be deflated by withdrawal of fluid fromballoon 20, through lumen 40, and out of side-access inflation port 22.

The low profile valve of the present invention may be used withcatheters such as that described above, all well as with differentcatheters having different structures. In one preferred embodiment, thelow profile valve comprises a sealing member which is movably positionedwithin the inner lumen of a catheter. The catheter has an inflationport, which, in some embodiments, is also an opening to the inner lumenat the proximal end of the catheter. An inflatable balloon is positionedon the distal end of the catheter, which is in fluid communication withthe lumen and inflation port. The sealing member is inserted through theproximal opening into the lumen, with a portion of the sealing memberextending outwardly from the proximal end of the catheter. The portionof the sealing member inserted into the lumen has a sealer portion whichforms a fluid tight seal with the inner lumen to prevent fluid frompassing past the sealer portion.

By application of a pushing or pulling force on the extending sealingmember portion, the sealing member may be partially advanced within orwithdrawn from the lumen, thereby moving the sealer portion within thelumen. In this manner, the sealer portion may be positioned within thelumen either proximally or distally of the inflation port. When thesealer portion is positioned proximally of the port, the valve is in the“open” position. When the valve is open, an unrestricted fluid pathwayis established between the inflation port and the balloon, such that anexternal pressurized fluid source may be connected to the inflation portto inflate the balloon, or if the balloon is already inflated, theballoon may be deflated by application of a vacuum to the inflation portto withdraw fluid from the balloon. When the sealer portion ispositioned distally of the inflation port, the valve is in the closedposition, as the fluid tight seal between the lumen and the sealerportion prevents fluid from passing either to or from the balloonthrough the inflation port. Furthermore, when the valve is closed afterballoon inflation, the fluid tight seal created by the sealer portionmaintains the balloon in the inflated state in the absence of anexternal fluid source, by preventing the pressurized fluid within theballoon from escaping.

Referring to FIGS. 2, 3A and 3B, there is depicted one embodiment of thelow profile valve of the present invention, as used with the catheter ofFIG. 1. Catheter 10, as described above, has a side-access inflationport 22 which is in fluid communication with central lumen 40, andthrough which fluid may be introduced to inflate balloon 20. Centrallumen 40 has an opening 23 at proximal end 12. A sealing member 30 isinserted into lumen 40 through opening 23. Sealing member 30 may bepartially advanced within or withdrawn from lumen 40 by the applicationof a longitudinal force on sealing member 30 directed toward or awayfrom proximal end 12, respectively.

Sealing member 30 comprises a main shaft 33, a tapering region 31, and awire 32. Sealing member 30 may be formed as solid piece out of suitablemetals, such as stainless steel, nitinol and the like. For example,sealing member 30 may be formed as a solid cylindrical piece, and thenbe coined down at points along its length to form tapering region 31 andwire 32. Alternately, one or more of the main shaft 33, tapering region31, or wire 32 may be formed separately, and then attached to the otherpiece(s) by conventional means, such as soldering, to form sealingmember 30. Polymeric materials, such as DELRON (TM), nylon, and thelike, may also be used to form sealing member 30, either as a solidpiece, or as separate pieces which are later joined to form the sealingmember.

Although not required, in one preferred embodiment, main shaft 33 has anouter diameter no larger than the outer diameter of the catheter tubularbody 18. Thus, if the outer diameter of tubular body 18 is 0.014 inches,the diameter of main shaft 33, and thus the largest diameter of sealingmember 30, is no larger than 0.014 inches. Furthermore, it is alsopreferred that main shaft 33 extend proximally from opening 23 by adistance of at least several centimeters to facilitate the applicationof longitudinal forces on main shaft 33 to manipulate the position ofwire 32 in lumen 40. Moreover, after catheter 10 has been fully insertedinto a patient, an extending main shaft 33 advantageously functions muchlike a conventional guidewire extension, providing a starting point forthe clinician to insert other catheters over main shaft 33 and catheter10.

The combined length of catheter 10 and extending main shaft 33 may bevaried considerably at the point of manufacture, and may be adapted tothe requirements of the other catheters which are to be used withcatheter 10 and main shaft 33. For example, where catheter 10 is to beused as a guidewire for other catheters in an “over-the-wire”embodiment, it is preferred that the total length of catheter 10 withextending main shaft 33 be about 300 centimeters. Alternately, whencatheter 10 is to be used as a guidewire for other catheters in a singleoperator embodiment, or “RAPID-EXCHANGE” embodiment, it is preferredthat the total length of catheter 10 with extending main shaft 33 beabout 180 centimeters. As can be readily appreciated, the individuallengths of catheter 10 and extending main shaft 33 can be variedconsiderably and yet still achieve the overall desired combined length.For example, a catheter 10 having a length of 180 centimeters can beprovided with an extending main shaft 33 having a length of 120centimeters, to achieve the 300 centimeter total desired length forover-the-wire embodiments.

In another embodiment, where it is undesirable to have a long main shaftextending proximally from catheter 10, a main shaft extending proximallyonly several centimeters may be provided. The shorter main shaft may beprovided with an attachment (not shown), which is adapted to releasablysecure longer extensions to the main shaft, such that it can also beused to facilitate the use of catheter 10 as a guidewire for othercatheters.

It is preferred that main shaft 33 have a larger diameter than the otherportions of sealing member 30, to make it easier to apply moving forcesto sealing member 30. Thus, a tapering region 31 may be disposed betweenmain shaft 33 and wire 32, to transition the outer diameter of sealingmember 30 from the larger diameter of main shaft 33 to the smallerdiameter of wire 32. For the embodiment illustrated in FIGS. 1-3, it iswire 32 which is slidably inserted through opening 23 and into lumen 40.Accordingly, the outer diameter of wire 32 must be less than the innerdiameter of lumen 40, so that wire 32 may be slidably accommodatedtherein. Moreover, in those embodiments where the end of wire 32 extendsdistally past inflation port 22 when the valve is in the open position,the gap between the outer diameter of wire 32 and the inner diameter oflumen 40 must be sufficiently large so as not to significantly restrictthe flow of fluid passing through lumen 40 to or from inflation port 22.Optimally, to facilitate the sliding of wire 32 within lumen 40 and topermit inflation fluid flow, wire 32 is from about 0.001 inches to about0.004 inches smaller in outer diameter than the inner diameter of lumen40.

In a preferred embodiment, wire 32 and catheter 10 are provided withpositive stops to prevent the withdrawal of wire 32 from the proximalend of catheter 10. For the embodiment depicted in FIGS. 3A and 3B, thisconsists of a pair of cooperating annular rings mounted on wire 32 andlumen 40, respectively. A first annular ring 34 is coaxially and fixedlymounted on wire 32 at a point on wire 32 contained within lumen 40. Asecond corresponding fixed annular ring 35 projects inwardly from theinterior surface of lumen 40 near proximal end 12. The inner diameter ofthe opening of annular lumen ring 35 is slightly larger than the outerdiameter of wire 32, so as not to restrict the movement of wire 32within lumen 40. However, the outer diameter of annular wire ring 34 isgreater than the inner diameter of the opening of ring 35, such thatrings 34 and 35 cooperate to prevent wire 32 from being withdrawn fromthe proximal end of catheter 10.

Rings 34 and 35 may be formed of any material which may be attached towire 32 and lumen 40, respectively, and which possesses sufficientstructural rigidity to act as a stop. Examples of suitable materials aremetals and various hard polymers, such as stainless steel and TEFLON(TM). In one preferred embodiment, where wire 32 and tubular body 18 areboth formed of nitinol, rings 34 and 35 are also formed of nitinol andare soldered to wire 32 and the inner surface of lumen 40, respectively.

As will be appreciated by those of skill in the art, cooperatingstopping structures other than those described herein may also be usedto prevent full withdrawal of wire 32 from catheter 10. For example,annular ring 34 may be replaced by one or more protrusions extendingradially outwardly from wire 32, which are also adapted to cooperatewith ring 35 to prevent withdrawal of wire 32. Alternately, annular ring35 might be replaced by crimping tubular body 18 slightly to restrictmovement of ring 34 to points proximal of the crimp.

A lumen sealer portion 36 is coaxially and fixedly mounted on wire 32.Sealer portion 36 is positioned on wire 32 at a point distal to ring 34,such that by partial withdrawal of wire 32 from catheter 10, as depictedin FIG. 3A, sealer portion 36 is capable of being positioned withinlumen 40 at a point proximal to inflation port 22. Sealer portion 36 isalso located on wire 32 at a point such that when wire 32 is fullyinserted into lumen 40, as depicted in FIG. 3B, sealer portion 36 eitherfully covers inflation port 22, or is located within lumen 40 at a pointdistal to inflation port 22. The leading edge 36 a and trailing edge 36b of sealer portion 36 are preferably tapered, so that the edges ofsealer portion 36 do not catch upon inflation port 22 when sealerportion 36 passes by port 22.

It is preferred that sealer portion 36 form a fluid tight seal with theouter diameter of wire 32 and the inner diameter of lumen 40, such thatfluid in lumen 40 is prevented from flowing past sealer portion 36. Inthe embodiment illustrated in FIGS. 3A and 3B, this is achieved byproviding wire 32 with a sealer portion 36 that firmly contacts theentire inner circumference of a section of lumen 40 along a substantialportion of the length of sealer portion 36. The fit between the outersurface of sealer portion 36 and the inner surface of lumen 40 is tight,such that a fluid tight seal is created which prevents fluid frompassing past sealer portion 36. However, sealer portion 36 must becapable of being moved within lumen 40 upon movement of main shaft 33,tapering region 31, and wire 32. Thus, the fit between sealer portion 36and lumen 40 must not be so tight as to prevent movement of sealerportion 36 in lumen 40 upon application of sufficient longitudinal forceon main shaft 33. Moreover, the fluid tight seal created by the fitbetween lumen 40 and sealer portion 36 must be maintained as sealerportion 36 is moved back and forth within lumen 40.

Sealer portion 36 must also be capable of maintaining a seal at fluidpressures conventionally used to inflate catheter balloons, and shouldbe capable of maintaining a seal at pressures which exceed conventionalinflation pressures. Preferably, sealer portion 36 is capable ofmaintaining a seal at pressures up to about 10 atmospheres, morepreferably pressures up to about 30 atmospheres, and most preferably atpressures up to about 60 atmospheres. Sealer portion 36 is alsopreferably capable of undergoing multiple valve-opening andvalve-closing cycles without losing the structural integrity required toform seals capable of withstanding pressures of from about 10atmospheres to about 60 atmospheres. Optimally, sealer portion 36 iscapable of undergoing at least 10, and preferably at least 20,valve-opening and closing events and still be capable of maintaining afluid tight seal at a pressure of 10 atmospheres.

In one preferred embodiment, the desired properties of sealer portion 36are attained by forming sealer portion 36 out of an extruded polymerictubing. PEBAX (TM) tubing having an inner diameter of 0.008 inches andan outer diameter of 0.017 inches, and a hardness of 40 durometers, isfirst necked by heating the extruded tubing to a temperature of between210 and 250 degrees Fahrenheit. Tube pieces of about 0.5 mm in lengthare then cut from the larger tubing. The cut PEBAX (TM) tubes are thenplaced on a nitinol wire having an outer diameter of about 0.006 inches,and are heated and shaped to recover a tube that has an outer diameterof between 0.010-0.011 inches. The adhesive Loctite 4014 (TM) may thenbe used to bond the heat-shaped PEBAX (TM) tubing to the nitinol wire.When the adhesive dries, the leading and trailing edges of the boundPEBAX (TM) seal may be trimmed, leaving an annular lumen contact lengthof about 0.010 inches (0.25 mm). The wire bearing the PEBAX (TM) sealerportion may then be inserted into the opening of a nitinol catheterhaving a lumen with an inner diameter of about 0.0096 inches. Sealerportions of this type have been observed to hold pressures of up to 30atmospheres, and are capable of undergoing multiple valve-opening andclosing events without significantly diminishing the seal strength.

It is contemplated by the present inventors that methods and materialsother than those described above may be used to make a lumen sealerportion having the desired properties. For example, materials other thanPEBAX (TM), silicone, latex rubber, C-FLEX (TM), Nusil (TM) and gels,which are known to possess adequate surface properties to function as asealer portion, and also be lubricous enough to be moved within lumen40, may also be used to form sealer portion 36. In addition, sealerportion 36 may be attached to wire 32 by alternate means, such as byintegrally molding sealer portion 36 to wire 32, dip forming sealerportion 36 to wire 32, as well as other means of attaching a polymericmaterial to a wire known to those of skill in the art.

Other embodiments of sealer portion may not create a completely fluidtight seal between the sealer portion and the inner lumen at ballooninflation pressures. In these embodiments, however, the sealer portioncreates a seal which prevents substantially all inflation fluid flowpast the sealer portion, such that the inflatable occlusive device ismaintained in an almost fully expanded state for extended periods of atleast one minute, preferably 2 or more minutes, more preferably at least10 minutes, and optimally at least 20 minutes or longer, and still becapable of providing clinically effective occlusion of any emboliparticles in the blood vessel during this time period.

In a preferred embodiment, there is provided movement-force increasingstructure, to increase the force required to move sealer portion 36 fromthe valve-closed to the valve-open position. Structure of this typeadvantageously minimizes the risk of an accidental opening of the valve,and subsequent balloon deflation, during a medical procedure. In theembodiment illustrated in FIGS. 3A and 3B, this achieved by providing abiasing spring 37, which surrounds wire 32 between stops 34 and 35.Spring 37 exerts a force on stop 34, pushing it, and thus wire 32 andsealer portion 36, in the distal direction, so that sealer portion 36forms a fluid tight seal by either covering port 22 or by beingpositioned within the lumen at a point distal to port 22. Consequently,in the absence of a competing force, spring 37 maintains sealer portion36 in the valve-closed position. Sealer portion 36 may be movedproximally to the valve-open position by application of a longitudinalforce on main shaft 33 directed proximally from end 12 of sufficientmagnitude to overcome the force of spring 37. Optimally, spring 37 isselected so that the force that must be applied to main shaft 33 toovercome the force of spring 37 is from about 0.3 to about 1.0pound-foot. In alternative embodiments, the movement force increasingstructure may comprise waves introduced into the wire just proximal ofthe sealer portion, as described below, which also may require 0.3 to1.0 pound-foot of force to overcome.

Referring to FIGS. 4 and 5, there is illustrated in alternativeembodiment of the valve of the present invention. The alternativeembodiment comprises a catheter 110 which may have features which aresubstantially identical, in materials, structure, and function, as thecatheter described in connection with FIGS. 1-3. Catheter 110 has aproximal end 112, and a distal end (not shown) to which is mounted anexpandable member, such as an inflatable balloon. A central lumen 140extends within tubular body 118 between the proximal and distal ends. Anopening 123 to lumen 140 is present at the proximal end 112 of catheter110.

A sealing member 130 is inserted into lumen 140 through opening 123, asdescribed previously. Sealing member 130 comprises a sealer portion 136,a wire 132, annular rings 134 and 135, and support member 150. Sealingmember 130 may be formed out of materials and by methods as describedpreviously.

As illustrated in FIGS. 4 and 5, the outer diameter of wire 132 is lessthan the inner diameter of lumen 140, such that sealing member 130 isslidably insertable into lumen 140. Furthermore, a lumen sealer portion136 is coaxially and fixedly mounted to wire 132 near the distal end ofwire 132. Sealer portion 136 forms a fluid tight seal with the outerdiameter of wire 132 and the inner diameter of lumen 140, such thatfluid introduced into lumen 140 through opening 122 is prevented fromflowing past sealer portion 136 at normal balloon inflation pressures of1 to 3 atmospheres for occlusive devices, and as much at 10 atmospheresor more for other types of balloons. Sealer portion 136 may be providedwith leading edge 136 a and trailing edge 136 b, both tapered, tofacilitate movement of sealing portion 136 proximally and distally ofinflation port 122. Sealer portion 136 forms a fluid tight seal byfirming contacting the entire inner circumference of a section of lumen140 along a substantial portion of the length of sealer portion 136. Asdescribed previously, sealer portion 136 prevents substantially allfluid flow past the seal created by sealer portion 136, and the movementof sealer portion 136 proximally and distally of port 122 may be used toeffect the valve-open and valve-closed positions.

Cooperating positive stops, consisting of hollow cylinders 134 and 135are provided to prevent withdrawal of sealing member 130 from lumen 140.Hollow cylinder 135 is attached to the inner surface of lumen 140 byadhesives, soldering, crimping, or by other means known to those ofskill in the art, such that the proximal portion of hollow cylinder 135extends within lumen 140, and is secured therein, and the distal portionof cylinder 135 extends from proximal end 112. Cylinder 135 has a lumen(not shown) extending therethrough. The diameter of the cylinder lumenis larger than the outer diameter of wire 132, so that movement of wire132 is not restricted. A second hollow cylinder 134, preferably ofshorter length, is placed over wire 132 and is fixedly mounted to wire132, by soldering, or other means, at a point distal to cylinder 135.The outer diameter of cylinder 134 is less than the inner diameter oflumen 140, so as not to restrict the movement of wire 132 within lumen140. However, the outer diameter of cylinder 134 is greater than theinner lumen diameter of cylinder 135, so that cylinders 134 and 135 actas cooperating stops, to prevent wire 132 from being withdrawn fromlumen 140. Cylinders 134 and 135 may be formed of any material which maybe attached to wire 132 and lumen 140, respectively, and which possessessufficient structural rigidity to act as a stop. Examples of suitablematerials are metals and various hard polymers, such as stainless steel,TEFLON (TM), and the like. In one preferred embodiment, where wire 132and tubular body 118 are both formed of nitinol, cylinders 134 and 135are also formed of nitinol, and are soldered to wire 132 and the innersurface of lumen 140, respectively.

The distal portion of cylinder 135 extending from proximal end 112 isinserted into support member 150. Support member 150 comprises a tubularbody 158 having an outer diameter and inner lumen diameter which areapproximately the same as tubular body 118. Consequently, because theouter diameter of cylinder 135 is less than the inner lumen diameter ofsupport member 150, the extending portion of cylinder 135 is slidablydisposed within the support member 150 inner lumen.

Wire 132 extends proximally from cylinder 135 within support member 150,as shown in FIGS. 4 and 5. A segment of wire 132 within support member150 is secured to support member 150 at point 152. Wire 132 may besecured to support member 150 by any means known to those of skill inthe art, including use of adhesives, crimping, soldering or welding.Because wire 132 is secured to support member 150, the application oflongitudinal forces on support member 150 results in movement of sealingmember 130 within lumen 140, to open or close the valve of the presentinvention, as described above with respect to FIGS. 1-3. Advantageously,use of support member 150 protects wire 132 from undesirable kinking orbending when sealing member 130 is moved.

As illustrated in FIGS. 4 and 5, sealing member 130 has movement-forceincreasing structure which increases the force required to move sealingmember 130 within lumen 140. The movement-force increasing structureconsists of waves 138 formed in wire 132 just proximal to sealer portion136. Waves 138 contact the inner surface of lumen 140, therebyincreasing the frictional forces which must be overcome to move wire 132within lumen 140. In one preferred embodiment, where wire 132 is made ofnitinol and has an outer diameter of 0.006 inches, and is inserted intoa nitinol catheter which has an inner lumen 140 with the diameter ofabout 0.010 inches, waves are formed on wire 132 for one and one-halfcycles with an amplitude of about 0.016 inches to increase thevalve-opening movement force.

Referring to FIGS. 6 and 7, there is illustrated another embodiment ofthe present invention. Referring to FIG. 6, there is provided a catheter400 having a tubular body 418 and inflatable balloon (not shown) asdescribed above. Catheter 400 may be formed of materials and methods asdescribed above, and may have structural aspects identical to thosedescribed previously, except where otherwise noted. In particular, asshown in FIGS. 6 and 7, catheter 400 is not provided with a side-accessport on the catheter tubular body, nor is there provided cooperatingpositive stops on the wire and lumen. Instead, the sealer portion may befully withdrawn from the lumen. Once the sealer portion is removed, theproximal opening serves as an access port for attached devices toinflate or deflate the balloon. The sealer portion can be insertedthrough the proximal opening into the lumen after balloon inflation tomaintain the balloon in the inflated state.

Catheter 400 has a proximal end 412, and a distal end (not shown) towhich is mounted an inflatable balloon. A central lumen 440 extendswithin tubular body 418 between the proximal and distal ends. An opening423 to lumen 440 is present at the proximal end 412 of catheter 400.

A sealing member 430 is inserted into lumen 440 through opening 423.Sealing member 430 has a main shaft 433, a tapering region 431, and awire 432. Sealing member 430 may be formed of materials and by methodsas described previously. As illustrated in FIGS. 6 and 7, the outerdiameter of main shaft 433 is less than the inner diameter of lumen 440,such that main shaft 433 is slidably insertable into lumen 440. Inaddition, the outer diameters of tapering region 431 and wire 432 arealso smaller than main shaft 433, and thus lumen 440, such that taperingregion 431 and wire 432 are also slidably insertable in lumen 440. Aportion of main shaft 433 preferably extends proximally from end 412, tofacilitate application of moving forces upon sealing member 430 to movewire 432 within lumen 440, as described previously.

As illustrated in FIGS. 6 and 7, sealing member 430 has movement-forceincreasing structure which increases the force required to move sealingmember 430 within lumen 440. The movement-force increasing structureconsists of waves 438 a and 438 b formed in wire 432 near its distalend. Waves 438 a and 438 b contact the inner surface of lumen 440,thereby increasing the frictional force which must be overcome to movewire 432 within lumen 440. In one preferred embodiment, where wire 432is made of nitinol and has an outer diameter of 0.006 inches, and isinserted into a nitinol catheter which has an inner lumen 440 with adiameter of about 0.010 inches, waves are formed on wire 432 for 1-½cycles with an amplitude of about 0.016 inches to increase thevalve-opening movement force.

A lumen sealer portion 436 is coaxially and fixedly mounted on wire 432.Sealer portion 436 forms a fluid tight seal with the outer diameter ofwire 432 and the inner diameter of lumen 440, such that fluid introducedinto lumen 440 through opening 423 is prevented from flowing past sealerportion 436 when sealer portion 436 is inserted into lumen 440. Sealerportion 436 forms the fluid tight seal by firmly contacting the entireinner circumference of a section of lumen 440 along a substantialportion of the length of sealer portion 436, and may be formed ofmaterials and by methods as previously described.

In some removable sealing member embodiments, the sealing member is notprovided with a separate sealing portion, as described above. In theseembodiments, the sealing member itself functions as a sealing portionwhich is inserted into the proximal opening to restrict fluid flow, andwhich may be partially or wholly removed to provide for a fluid pathwaybetween the proximal opening and an expandable member on the distal endof the catheter. Preferably, the sealing members of these embodimentscomprise a tapering rod, which at its distal end, has an outer diametersmaller than the inner lumen diameter of the catheter in which it isinserted as a plug, such that the distal end of the rod may be easilyinserted into the catheter lumen through the proximal opening. Thetapering rod increases in outside diameter at points proximal to thedistal end. Consequently, one or more points of the rod have an outsidediameter greater than the inner lumen diameter of the catheter in whichit is inserted as a plug, such that by forcing the rod into proximalopening, the larger outer diameter of the rod forms a relatively fluidtight seal with the catheter lumen at the proximal opening of thecatheter. An O-ring, or other polymeric structure, may be mounted in theinner lumen of the catheter at or near the proximal opening, tocooperate with the tapering rod in the creation of the seal. Thus, inthis embodiment, the point where the seal is created does not move withrespect to the catheter, but is instead stationary at or near theproximal opening of the catheter.

Referring to FIG. 12, there is depicted an alternative embodiment of thevalve the present invention. The alternative embodiment is provided to acatheter 500, formed of a tubular body 518 and having a proximal end512. Catheter 500 has an opening 523 at is proximal end, and a lumen 540extending the length of the tubular body. Lumen 540 is in fluidcommunication with an expandable member (not shown) mounted on thedistal end of tubular body 518. A side-access port 522 is provided intubular body 518 at a point distal to proximal end 512. Catheter 500 mayhave aspects identical, both in structure, dimensions, materials, andconstruction, to catheters described previously.

A sealing member 550 is positioned within lumen 540 near proximalopening 523 and side-access port 522. Sealing member 550 is formed froma short tubular body 568, having a lumen 590, which is sealed at end562, but open at the other end. Sealing member 550 has an outer diameterslightly larger that the inner diameter of lumen 540, but smaller thanthe outer diameter of tubular body 518, such that sealing member 550 maybe tightly fit within lumen 540 through opening 523, to form a fluidtight seal over catheter proximal opening 523. Cooperating stoppingstructures (not shown) may be provided to sealing member 550 andcatheter 500 to prevent removal of sealing member 550 from lumen 540 atelevated pressures. Sealing member 550 may be formed out of the samematerials as tubular body 518.

Tubular body 568 is provided with an opening 572 extending therethrough.Opening 572 is positioned on tubular body 568 such that opening 572 iscapable of aligning with side-access port 522 when sealing member 550 isrotated within lumen 540, or is moved proximally or distally withinlumen 540. A rotation element 595, such as a perpendicular attachment,may be provided facilitate rotation of sealing member 550 within lumen540. Other rotation elements, such as notches or grooves, may be used inplace of the perpendicular attachment, as will be appreciated by thoseof skill in the art.

Sealing member 550 functions as a valve within catheter 500, controllingfluid flow through side-access port 522. When sealing member 550 isrotated so that port 522 and opening 572 are aligned, fluid may flowthrough port 522 through lumen 540 to inflate the occlusive device. Uponthe desired inflation, sealing member 550 may be rotated, as for exampleby ninety degrees, or moved proximally or distally within lumen 540,such that opening 572 is no longer aligned with port 522, and tubularbody 568 blocks fluid flow through port 522.

Shown in FIG. 13, is an alternative embodiment of the rotatable sealingmember. Numerals corresponding to those of the embodiment of FIG. 12have been used to illustrate the similar structural aspects between thetwo embodiments. Sealing member 600 is identical in construction to thesealing member of FIG. 12, except that sealing member 650 is somewhatlarger, and is adapted to be slipped over tubular body 618. Therespective diameters of tubular body 618 and sealing member lumen 690are such that a fluid tight seal is created over lumen 623. Side-accessinflation port 622 may be aligned with opening 672, as above, byrotation or longitudinal movement, to provide fluid access to lumen 640through port 622.

In certain embodiments, it may be desirable for sealing members 550 and650 to have a longer length, such that they may function as an extensionfor other catheters to be inserted over catheters 500 and 600. In theseembodiments, sealing members 550 and 650 may be formed with longertubular bodies, or be provided with attachments so that extensionmembers may be releasably secured thereto.

Referring to FIGS. 14, 15A and 15B, there is illustrated an alternativeembodiment of the present invention featuring a self-closing valve. Thealternative embodiment comprises a catheter 700 having an elongateflexible tubular body 718 extending between a proximal control end 712and a distal functional end (not shown), and having a balloon (notshown) as described previously. Tubular body 718 has central lumen 740which extends between the proximal and distal ends. Lumen 740 has anopening 723 at proximal end 712, and is sealed fluid tight at the distalend. A side access inflation port 722 is formed in tubular body 718 at apoint distal of opening 723. Inflation port 722 and lumen 740 are influid communication with the distal inflatable balloon, as describedpreviously.

A wire 732 is inserted into opening 723, and is slidably disposed withinlumen 740. Accordingly, the outer diameter of the wire 732 must be lessthan the inner diameter of lumen 740, so that wire 732 may be slidablyaccommodated therein. A sealer portion 736 is coaxially mounted on wire732. Sealer portion 736 is of similar type and construction to thesealer portion described in connection with FIGS. 1-3. Sealer portion736 is positioned on wire 732 at a point distal to inflation port 722,and forms fluid-tight seal with the outer diameter of wire 732 and theinner diameter of lumen 740, such that fluid introduced into lumen 740is prevented from flowing past sealer portion 736. Consequently, becausesealer portion 736 is positioned with lumen 740 distal to inflation port722, sealer portion 736 is in the valve-closed position.

In the embodiment depicted in FIGS. 14-15B, tubular body 718 is formedfrom a material having a certain degree of elasticity, such that if theproximal end 712 of tubular body 718 is secured to wire 732 at point750, and a longitudinal force is applied to tubular body 718 in adirection distal to end 712, the elasticity of tubular body 718 resultsin the shifting of inflation port 722 in the distal direction. Moreover,slits 711 may be formed in tubular body 718 near proximal end 712 toenhance the elastic response of tubular body 718, thereby increasing thedistal translocation of inflation port 722 upon application of an axialforce to tubular body 718. Wire 732 may be secured to tubular body 718by any means known to those of skill in the art, such as adhesives,welding, soldering, or crimping.

In a preferred embodiment, tubular body 718 is made out of nitinol, andhas at least 8% elasticity when longitudinal slits 711 are introduced atthe proximal end. As can be observed in FIG. 15A, in the absence of anylongitudinal force applied to tubular body 718, sealer portion 736 ispositioned within lumen 740 at a point distal to inflation port 722,such that fluid may not pass through port 722 to inflate or deflate theballoon. However, if a longitudinal force is applied to tubular body 718in the distal direction, and the proximal end of tubular body 718 andwire 732 are held in position, tubular body will stretch, as shown inFIG. 15B, and inflation port 722 will be translocated in the distaldirection so that sealer portion 736 will be located within the lumenproximally of port 722. This will establish an unrestricted fluidpathway between inflation port 722 and the distal balloon, so that theballoon may be either inflated or deflated by passage of fluid throughport 722. Upon removal of the longitudinal force, the elastic responseof tubular body 718 will result in proximal translocation of inflationport 722, and sealer portion 736 will once again be in the valve-closedposition.

Referring to FIGS. 8 and 9A, there is illustrated an inflation adaptor200 which may be used to inflate and to open and close the low profilevalve depicted in FIGS. 1-5. Inflation adaptor 200 comprises a housinghaving a first half 202 and a second half 204, which are preferablyformed of metal, medical grade polycarbonate, or the like. Halves 202and 204 are attached to one another by a pair of hinges 205 positionedon one of the lateral edges of each half, such that halves 202 and 204may be separated or joined in a clam shell manner as depicted in FIGS. 8and 9. A locking clip 230 secures half 202 to half 204 while inflationadaptor 200 is in use. Locking clip 230 may be provided with an angledleading edge 235 to facilitate closing of clip 230 to secure halves 202and 204 together. Springs 209 may also be provided to facilitate openingof adaptor 200.

A groove 240 separates first half 202 from second half 204 when thehalves are closed and clip 230 is secured. Groove 240 is of sufficientwidth to accept the proximal end of a catheter having the low profilevalve of the present invention, as described in detail above. A fitting210 is positioned on half 202, to create an inflation passageway 212which terminates in opening 285 on the interior surface of first half202. Fitting 210 is preferably a standard luer connector which may beattached to a variety of existing external pressurized fluid sources,although other types of fittings, such as tubings, quick connects, andY-site connections, may be easily substituted for a luer fitting.

A seal comprising a pair of gaskets 280 is positioned around opening 285on the interior surfaces of halves 202 and 204. Gaskets 280 are inalignment, such that when halves 202 and 204 are brought together andsecured by locking clip 230, a fluid tight inflation chamber is createdwithin the interior region defined by gaskets 280. The fluid tightinflation chamber is in fluid communication with fitting 210 viainflation passageway 212, so that a pressurized inflation fluid may beintroduced into the fluid tight inflation chamber by attaching anexternal pressurized fluid source to fitting 210. Moreover, gaskets 280are preferably formed of resilient materials, such as silicone, C-FLEX(TM) and PEBAX (TM), so that gaskets 280 may form-fit over a cathetertubular body which extends across the lateral edges of gaskets 280, tocreate the fluid tight chamber.

An actuator 220 is positioned on the external surface of half 202. Inthe embodiment illustrated in FIGS. 8 and 9, actuator 220 controls a camwhich operates a sliding panel 283 on the interior surface of half 202.Sliding panel 283 moves back and forth along a line which bisectsopening 285. When actuator 220 is moved to a first position, slidingpanel 283 moves toward opening 285 along this line. When actuator 220 ismoved to a second position, sliding panel 283 moves away from opening285 along the same line. A corresponding sliding panel 284 is positionedon half 204, such that panels 283 and 284 are aligned and move togetherwhen the position of actuator 220 is changed. To facilitate coordinatedmovement of panels 283 and 284, a pin 286, or such other similarengagement structure, may be provided to releasably secure panel 283 topanel 284 when the adaptor is closed. The length of travel of panels 283and 284 is preferably adjusted to provide the minimum sufficientdistance to position the sealing member in the valve open or valveclosed position, as desired.

Panels 283 and 284 each have a roughened surface 290, to facilitate thefrictional engagement of panels 283 and 284 with the main shaft portionof the low profile valve. In a preferred embodiment, panels 283 and 284are both made of silicone, and roughened surface 290 comprises teeth 291and grooves 292 formed on each of panels 283 and 284. The teeth 291 andgrooves 292 cooperate, to permit the teeth of one panel to fit into thegrooves of the opposite panel when the adaptor is closed.

For ease of understanding, the operation of inflation adaptor 200 toinflate the balloon of the catheter of FIGS. 1-3 will now be described.Actuator 220 is moved to the first position, so that sliding panels 283and 284 are moved closer to opening 285. Locking clip 230 is thenundone, exposing groove 240. Halves 202 and 204 are then partiallyseparated, and catheter 10, with the balloon 20 deflated, is insertedinto the inflation adaptor. As described previously, catheter 10 has aninflation port 22 located near proximal end 12, and a main shaft 33extending from proximal end 12. Catheter 10, with the low profile valvein the closed position, is placed within groove 240 of partially openadaptor 200, and catheter 10 and main shaft 33 are placed withinsecuring clips 271 and 272, such that when halves 202 and 204 areclosed, inflation port 22 will lie within the fluid tight inflationchamber created by gaskets 280, and the extending portion of main shaft33, but not proximal end 12, will rest between sliding panels 283 and284. An alignment slot 298 and overlying shelf 299 may be provided tofacilitate alignment and prevent buckling or kinking of the catheter andsealing member during use.

As shown in FIG. 9B, in one embodiment, indicia 260 are provided oncatheter 10 and main shaft 33, which when aligned with indicia 270 oninflation adaptor 200, result in alignment of inflation port 22 with thefluid tight inflation chamber of adaptor 200, and alignment of mainshaft 33 with sliding panels 283 and 284, when catheter 10 and sealingmember 30 are inserted into groove 240. Indicia 260 and 270 may take theform of markings, grooves or notches, or any other suitable means ofaligning the valve with the inflation adaptor alignment indicia, may beprovided. Preferably, the gap between indicia 260 on catheter 10 andmain shaft 33 is approximately equal to the space between clips 271 and272, such that by placing indicia 260 within clips 271 and 272, catheter10 and main shaft 33 are properly aligned within adaptor 200.

Once main shaft 33 and inflation port 22 are properly aligned withinadaptor 200, locking clip 230 is secured. Inflation port 22 now lieswithin the fluid tight inflation chamber created by gaskets 280, andmain shaft 33 rests between sliding panels 283 and 284. The clinicianmay then attach an external pressurized fluid source to fitting 210.

To inflate balloon 20, the clinician moves actuator 220 from the firstposition to the second position, thereby causing sliding panels 283 and284 to move away from opening 285. Because main shaft 33 is firmlysecured between panels 283 and 284, a longitudinal force directed awayfrom proximal end 12 is applied to main shaft 33. The longitudinal forceon main shaft 33 results in wire 32 being partially withdrawn from lumen40, which causes sealer portion 36 on wire 32 to be moved to a positionwithin lumen 40 which is proximal of inflation port 22. The movement ofsealer portion 36 proximally of inflation port 22 opens the low profilevalve, by establishing an unrestricted fluid pathway between inflationport 22 and balloon 20.

The external pressurized fluid source may then be activated, as forexample by pushing the plunger on a syringe, such that pressurized fluidpasses through passageway 212 and opening 285 into the fluid tightinflation chamber. The pressurized fluid then passes through inflationport 22 and lumen 40, to inflate balloon 20.

Inflated balloon 20 may be maintained in the inflated state, in theabsence of the pressurized fluid source, by closing the low profilevalve. This is accomplished by moving actuator 220 back to the firstposition, thereby causing sliding panels 283 and 284 to move towardopening 285. The moving panels apply a longitudinal force, directedtoward proximal end 12 to main shaft 33, causing wire 32 to be furtherinserted into lumen 40. Consequently, sealer portion 36 is moved from aposition within lumen 40 which is proximal to inflation port 22 to aposition in lumen 40 which is distal to inflation port 22. The fluidtight seal created by sealer portion 36 traps the pressurized fluidwithin lumen 40 and balloon 20, thereby maintaining balloon 20 in theinflated state. The external pressurized fluid source may then bedeactivated and removed. Once the low profile valve is closed, inflationadaptor 200 may be removed by unlocking clip 230, and removing catheter10 and main shaft 33 from groove 240.

Referring to FIGS. 10 and 11, there is illustrated an alternativeembodiment of an inflation adaptor especially adapted for manipulatingremovable low profile valves, although it may be used with side-accessembodiments as well. Adaptor 300 comprises an outer sleeve 320 formed ofmetal, medical grade polycarbonate, or similar such materials. Outersleeve 300 defines a tapering inner lumen 350. Lumen 350 tapers fromlarge diameter 352 which is significantly greater than the outerdiameter of the catheter tubular bodies inserted into lumen 350, to asmaller diameter 355, which is slightly larger the outer diameter of thecatheter tubular body. Lumen 350 is in fluid communication with aninflation passageway 312 formed by fitting 310, so that a pressurizedinflation fluid may be introduced into lumen 350. Releasable seals 315are positioned at each end of lumen 350, such as to create a fluid tightinflation chamber within lumen 350 when a pressurized fluid source isattached. Releasable seals 350 may comprise any type of seal known tothose of skill in the are, such as Toughy Borst connectors, hemostaticvalves, and the like. Releasable seals 350 may also act to secure anycatheters and sealing members inserted within the releasable sealopenings 325.

In use, a catheter and sealing member, such as that described inconnection with FIGS. 6-7, is inserted into opening 325 after seals 315have been opened. The catheter and sealing members are positioned underpassageway 312, and the sealing member is removed from the proximalopening of the catheter. A fluid passageway is thereby created betweenthe proximal catheter opening and the expandable member of the distalend of the catheter. Seals 350 are closed to create a fluid tightchamber, and a vacuum and/or pressurized inflation fluid is applied, toinflate or deflate the balloon. After the desired inflation or deflationhas occurred, the sealing member may be introduced into the proximalopening of the catheter tubular body to seal the lumen, either by handor by a movable actuator (not shown). Seals 350 may then be loosened,and the end access adaptor 300 removed by sliding the adaptor off theend of the catheter and sealing member.

What is claimed is:
 1. A valve, comprising: a flexible elongate tubularbody having a proximal end and a distal end, and a lumen having alongitudinal axis extending between the proximal and distal end, thelumen having an opening at the proximal end; an expandable member on thedistal end of the tubular body, the expandable member being in fluidcommunication with the lumen; an access opening on the tubular body, theaccess opening being in fluid communication with the lumen to permit theexpandable member to be actuated by pressurizing the access opening; asealing member having a sealer portion which seals against a surface ofthe tubular body, said portion of the sealing member being movable alongthe longitudinal axis relative to said surface of the tubular bodybetween two positions, one of the positions positioning the sealerportion in contact with said surface at a location which blocks the flowof fluid to and from the expandable member through the access opening tomaintain actuation of the expandable member, the other of the positionspositioning the sealer portion at a location which permits the flow offluid to and from the expandable member through the access opening topermit actuation or deactuation of the expandable member.
 2. The valveof claim 1, wherein the sealing member has a portion which extends fromthe proximal end of the tubular body, and wherein the application of aproximal longitudinal force on the extending portion results in proximalmovement of the sealer portion within the lumen, and the application ofa distal longitudinal force of the extending portion results in a distalmovement of the sealer portion within the lumen.
 3. The valve of claim2, further comprising force-increasing structure which increases thelongitudinal force which must be applied to the extending portion tomove the sealer portion.
 4. The valve of claim 1, wherein the sealerportion is formed from a polymeric material.
 5. The valve of claim 1,wherein the sealer portion is capable of withstanding pressures up to 10atmospheres while preventing substantially all fluid from passing to andfrom the balloon through the access opening when the sealer portion ispositioned distal to the access opening.
 6. The valve of claim 5,wherein the sealer portion is capable of undergoing 10 valve-opening andclosing cycles and, at a pressure of ten atmospheres, still preventssubstantially all fluid from passing to and from the balloon through theaccess opening when the sealer portion is positioned distal to theaccess opening.
 7. The valve of claim 1, wherein at least a portion ofthe sealing member is formed of a metal selected from the groupconsisting of nitinol, stainless steel and combinations thereof.
 8. Thevalve of claim 1, wherein the outer diameter of the tubular body islarger than the outer diameter of any portion of the sealing member orsealer portion.
 9. The valve of claim 8, wherein the outer diameter ofthe tubular body is no greater than 0.038 inches.
 10. The valve of claim9, wherein the outer diameter of the tubular body is no greater than0.020 inches.
 11. The valve of claim 10, wherein the outer diameter ofthe tubular body is no greater than 0.014 inches.
 12. The valve of claim1, further comprising positive stops to prevent withdrawal of thesealing member from the opening.
 13. The valve of claim 1, furthercomprising an inflation adaptor capable of receiving the valve, theinflation adaptor providing a fluid tight chamber for introduction of apressurized fluid to expand the expandable member.
 14. The valve ofclaim 1, wherein the access opening is the lumen opening.
 15. The valveof claim 1, wherein the lumen has a cross section which is substantiallyconstant from the proximal end to the distal end.
 16. The valve of claim1, wherein said one of the positions positioning the sealer portion incontact with said surface at a location which blocks the flow of fluidto and from the expandable member is distal to said other of thepositions positioning the scaler portion at a location which permits theflow of fluid to and from the expandable member.
 17. A valve,comprising: a flexible elongate tubular body having a proximal end and adistal end, and a lumen extending between the proximal and distal end,the lumen having an opening at the proximal end; an expandable member onthe distal end of the tubular body, the expandable member being in fluidcommunication with the lumen; an access opening on the tubular body, theaccess opening being in fluid communication with the lumen to permit theexpandable member to be actuated by pressurizing the access opening,wherein the access opening comprises a side-access port positioned onthe tubular body at a point proximal to the tubular body distal end; anda sealing member having a sealer portion which seals against a surfaceof the tubular body, said portion of the sealing member being movablerelative to said surface of the tubular body between two positions, oneof the positions positioning the sealer portion in contact with saidsurface at a location which blocks the flow of fluid to or from theexpandable member through the access opening to maintain actuation ofthe expandable member, the other of the positions positioning the sealerportion at a location which permits the flow of fluid to or from theexpandable member through the access opening to permit actuation ordeactuation of the expandable member.
 18. An apparatus, comprising: ahollow metallic guidewire having a central lumen and a side-access portin fluid communication with the lumen; an inflatable balloon mounted onthe guidewire, the inflatable balloon being in fluid communication withthe central lumen, such that fluid introduced through the side-accessport can be used to inflate the balloon; a valve mounted to slide alonga surface of the guidewire, said valve movable between first and secondpositions, one of said positions sealing the central lumen such thatsubstantially no fluid may pass to or from the inflatable balloon by wayof the side-access port.
 19. The apparatus of claim 18, wherein thehollow guidewire has an outer circumference defining a first value, andwherein the movable valve has a circumference which is less than thefirst value.
 20. The apparatus of claim 19, wherein the hollow guidewirehas an outer circumference of 0.044 inches or less.
 21. The apparatus ofclaim 18, wherein the movable valve has a diameter not substantiallylarger than that of the hollow guidewire, and wherein said valve sealsagainst an interior surface of said hollow guidewire.
 22. A low profilecatheter valve, comprising: a sealing member capable of being movablyinserted through a proximal opening on a catheter into an inflationlumen of the catheter, the catheter having a side-access inflation portand an inflatable balloon in fluid communication with the side-accessinflation port; a sealer portion on the sealing member, the sealerportion being capable of forming a fluid tight seal with the entirecircumference of a section of the lumen, such that substantially allfluid may not pass the sealer portion; wherein when the sealer portionis positioned within the lumen proximally of the side-access inflationport, an unrestricted fluid pathway is established between theside-access inflation port and the balloon, and when the sealer portionis positioned within the lumen distally of the side-access inflationport, substantially all fluid may not pass to or from the balloonthrough the side-access inflation port.
 23. The valve of claim 22,wherein the lumen has a cross section which is substantially constantfrom the proximal end to the distal end.
 24. A method of inflating acatheter balloon, comprising the steps of: providing a tube having aproximal end and a distal end, the proximal end having an inflationopening in fluid communication with an inflation lumen and the distalend having an inflatable balloon in fluid communication with theinflation lumen; introducing a pressurized inflation fluid through theinflation opening to inflate the balloon; sealing the inflation openingby moving a sealing member within the inflation lumen without reducingthe pressure of the pressurized fluid, wherein the step of sealing isperformed without deflating the inflated balloon; and reducing thepressure of the pressurized fluid after completing the sealing step. 25.The method of claim 24, wherein the lumen has a cross section which issubstantially constant from the proximal end to the distal end.
 26. Themethod of claim 24, wherein the inflation opening comprises aside-access port.
 27. A low profile catheter valve for use with aninflation adaptor, comprising: a catheter having an inflatable memberand an inflation opening for inflating the inflatable member, theinflatable member being in fluid communication with the inflationopening; a sealing member movably mounted in the catheter forselectively blocking fluid flow between the inflation opening and theinflatable member; indicia on at least one of said catheter and saidsealing member, the position of the indicia being such that alignment ofsaid indicia with corresponding indicia on the inflation adaptor causesthe inflation opening to be disposed within a fluid tight inflationchamber of the inflation adaptor.
 28. The low profile catheter valve ofclaim 27, wherein the lumen has a cross section which is substantiallyconstant from the proximal end to the distal end.
 29. The low profilecatheter valve of claim 27, wherein the inflation opening comprises aside-access port.
 30. A medical device apparatus, comprising: a flexibleelongate tubular body having a proximal end and a distal end, and alumen having a longitudinal axis extending between the proximal end andthe distal end, the lumen having an opening at the proximal end; anexpandable member on the distal end of the tubular body; an elongatemember having a portion which engages a surface of the tubular bodywithin the lumen of the tubular body, said portion being movable alongthe longitudinal axis relative to said surface of the tubular bodybetween two positions, one of the positions positioning the portion incontact with said surface at a location for maintaining actuation of theexpandable member.
 31. The apparatus of claim 30, wherein the expandablemember is an inflatable balloon.
 32. The apparatus of claim 30, whereinthe elongate member includes a sealer portion that seals against asurface of the tubular body.
 33. The apparatus of claim 30, wherein theouter diameter of the tubular body is larger than the outer diameter ofany portion of the elongate member.
 34. The apparatus of claim 30,wherein the elongate member includes waves that frictionally engage asurface of the tubular body within the lumen.
 35. The apparatus of claim30, wherein the lumen has a substantially constant cross-section fromthe proximal end to the distal end.
 36. The apparatus of claim 30,wherein the elongate member extends proximal to the tubular body.